Reinforced acoustical unit



Feb. 20, 1962 w. G. KEMP 3,021,916

REINFORCED ACOUSTICAL UNI-T Filed April 6, 1959 FIG-.5.

INVENTOR.

WILLiAZ EG.KEMP

ATTORNEiS United States Patent Qfihce 3,021,916 Patented Feb. 20, 1962 3,021,916 REINFORCED ACOUSTICAL UNIT William G. Kemp, 2275 E. Hammond Lake Drive, Pontiac, Mich. Filed Apr. 6, 1959, Ser. No. 864,393 13 Claims. (Cl. 181--33) This invention relates generally to reinforced acoustical units and refers more particularly to an acoustical panel including a light weight semi-rigid core comprising a honeycomb structure for strength and sound absorbing material between the cells of the honeycomb structure to deaden sound, and also including a reflecting pan bonded to the core on one side to reflect sound into the sound absorbing material and a perforated member bonded to the other side of the core and constructed to facilitate the installation and removal of the panel.

It is therefore one of the objects of this invention to provide a light weight acoustical panel having improved strength and rigidity.

Another object is to provide an acoustical panel for a ceiling structure including means to prevent sound from escaping from around the edges of individual panels into the area above the ceiling above a first room and back into an adjacent room when the rooms are separated by a common partition extending only ceiling high.

Another object is to provide an acoustical panel including means to prevent undesirable engagement of the panel with the supporting members therefor.

More specifically it is an object to provide an acoustical panel including a light weight semi-rigid core secured between a perforated bottom pan and an upper sound reflecting pan.

Still more specifically it is an object to provide an acoustical panel adapted to be supported on T-bars and including a lower perforated pan having edges upturned to form an angle of less than ninety degrees with the inner surface of the pan and extending less than the full height of the pan to prevent said edges from interfering with the removal of the panel from the T-bar supports therefor.

Still more specifically it is an object to provide an acoustical panel including an upper sound reflecting pan having the edges thereof turned down and extending to the inside of the lower surface of the perforated pan of the panel as installed.

These and other objects, advantages and novel details of construction of this invention will be made more apparout as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

FIGURE 1 is a plan view of the acoustical panel of the invention looking at the normally exposed surface thereof with the normally exposed surface partly broken away.

FIGURE 2 is a section through the acoustical panel of FIGURE 1 on the line 22 in FIGURE 1.

FIGURE 3 is a section through the acoustical panel of FIGURE 1 on the line 3-3 in FIGURE 1.

FIGURE 4 is an enlargement of the right end of FIGURE 3 showing the acoustical panel supported on a T-bar above a ceiling height partition between adjacent rooms.

I FIGURE 5 is a partly broken away perspective view of a corner portion of the acoustical panel of FIGURE 1.

One embodiment of the acoustical panel of the invention generally indicated is shown in the figures. The panel 10 as shown includes a perforated pan 12 for exposure to sound which it is desired to deaden, a reflecting pan 14 positioned behind the perforated pan 12 with respect to sound which it is desired to deaden for reflecting sound which passes through the perforated pan and strikes the reflecting pan back toward the perforated pan, and a light weight semi-rigid core 16, com-prising a honeycomb structure 52 having sound deadening material 54 between the cells thereof, positioned between the perforated pan 12 and the reflecting pan 14 and secured to both for deadening the sound passing therethrough and for adding strength and rigidity to the complete acoustical panel.

The perforated pan 12 is a substantially flat rectangular member having a plurality of orifices 118 therein. The orifices 18 may be in either a regular or irregular pattern and are provided to allow sound to pass into the interior of the panel 10 where it is deadened by the sound deadening material '54 of the core 16. The pan 12 may be molded, stamped or otherwise produced from metal, plastic or other suitable material. The material should present a smooth relatively rigid hard outer pan surface capable of being cleaned with ease since the outer pan surface will be exposed to view in a finished acoustical installation.

As shown the perforated pan 12 has edges upturned to form sides 20, 22, 24, and 26 at an angle of less than ninety degrees with respect to the general flat interior surface 28 of pan 12. Sides 20, 22, 24 and 26 as shown extend for only a part of the depth of the completed panel 10. In a complete panel as best shown in FIGURES 2 and 3 of the drawings the sides 20, 22, 24 and 26 of the perforated pan abut sides 30, 32, 34 and 36 of the reflecting pan. The free edges 38, 40, 42 and 44 of the sides 20, 22, 24 and 26 do not therefore form corners of the complete panel 10. The edges 38, 40, 42 and 44 are also not extending outwardly from the complete panel 10. Therefore, as. shown best in FIGURE 4 in the installation of a panel 10 or removal thereof from an installation wherein the panel 10 is supported on T- bars such as 46 or similar structure the edges 38, 40, 42 and 44 will not catch on the supporting structure making removal or installation thereof diflicult.

The reflecting pan 14 as shown is a substantially flat rectangular member. Reflecting pan 14 may also be molded, stamped or otherwise formed of metal, plastic or other suitable material. The pan 14 should have a relatively smooth hard dense inner surface in order to efliciently carry out its sound reflecting function. As shown best in FIGURE 4, wherein the direction in which sound which it is desired to deaden is traveling is indicated by arrow 48, the reflecting pan 14 is positioned behind the perforated panel 12 with respect to the direction of travel of the noise so that sound passing through perforated pan 12 and striking the reflecting pan 14 will be reflected back toward the perforated pan 14 through the sound deadening material 54 of core 16 as later considered in more detail.

It will also be noted that the reflecting pan 14 is provided with edges turned down to form sides 30, 32, 34 and 36 previously referred to and that the outer surface 49 of pan 14 is shorter in length and width than the outer surface 51 of pan 12. With this construction, in a completely assembled panel 10 the sides of the reflecting pan 14 and perforated pan 12 form complete panel sides presenting no outstanding edges to engage supports such as T-bar 46 and thereby interfere with installation or removal of the panel 10. Further it will be noted that in the completed panel 10 the sides 30, 32, 34 and 36 extend from the upper surface 49 of the reflecting pan 14 to the inner surface 28 of perforated pan 12. Through such construction sound is prevented from escaping from around the edges of the panel 10 by being reflected back into the sound deadening material. Such construction also allows the complete pan 12 including sides 20, 22,

24 and 26 to be perforated without harm to the acous- The core 16 is provided between pans 12 and 14 to increase the strength and rigidity of the assembled panel and to deaden the sound passing therethrough. The core 16 comprises a honeycomb structure 52 of plastic, asbestos, paper, or other suitable core material bonded to both the reflecting pan 14 and the perforated pan 12, the individual cells of which are filled with loose sound deadening material 54 such as plastic fibre, glass fibre, wool or the like. The core 16 may alternatively be foamed plastic, expanded metal or other light weight semi-rigid material in combination with separate sound deadening material 54.

The semi-rigid light weight core 16 is positioned between and bonded to the pans 12 and 14 provides a structure which is extremely resistant to deformation under both bending and twisting stresses. Such structure besides having excellent acoustical properties may be cut around openings in an acoustically treated surface or at the edge of the surface without providing special framing to prevent sagging or warping of the panels. Therefore panels constructed as herein described have the advantages of not only being simply constructed in themselves as is evident frorn inspection thereof, but are also simple and economical to install. Further economy in construction exists due to the high strength weight ratio of the panels 10 constructed with core 16 which permits larger panels to be used to cover an area to be acoustically treated thereby requiring less supporting structure and installation time.

In use the panel 10 constructed as shown is suspended on T-bars such as 46 or otherwise positioned with its perforated surface exposed to sound to be deadened. As above indicated the sound passes through the perforated pan 12, through the sound deadening core 16 to the reflecting pan 14 where the sound which has not been deadened by passage through the core material is reflected back into the core material to be further deadened thereby. The sides 30, 32, 34 and 36 of reflecting pan 14 extending the full depth of the panel 10 as shown prevent sound from escaping from the panel around the edges thereof by also reflecting sound coming in contact therewith back into the sound deadening core. Thus efficient use is made of the sound deandening core by causing sound to pass therethrough a plurality of times and preventing escape of sound from the panels 10 once it has entered the panels.

It will also be noted in referring to FIGURE 4 that in use the edges of assembled panel 10 constructed as disclosed present no outstanding projections which are likely to interfere with support members such as 46 on installation or removal from an installation of an acoustical panel 10. This is possible due to the less than ninety degree angle made by the sides of pan 12 with the interior surface 28 thereof and the fact that surface 49 of pain 14 is shorter in length and width than surface 51 of pan 12 as best shown in FIGURES 2, 3 and 4 wherein sides 30, 32, 34 and 36 of pan 14 are illustrated as nesting within the shorter sides 20, 22, 24 and 26 of pan 12.

With further reference to FIGURE 4 it can be seen that the honeycomb structure 52 serves also to prevent sound from entering the panel 10 on one side of a ceiling height partition 56 and passing directly through the panel 10 to the other side of the partition 56 as indicated by 'arrow 58. With the honeycomb part of the core 16 dimensioned so that the individual cells are less in width than the partition 56 as shown, any sound passing into the panel 10 on one side thereof will impinge on at least one cell wall of the honeycomb structure 52 and will be at least partly reflected back into the sound absorbing material 54 as indicated by arrow 60. The sound will thereby be prevented from passing unhindered from one side of partition 56 to the other.

The panel will be seen to have a multiplicity of sound isolation cells bonded by the walls of the honeycomb and by the surfaces 28 and 49 of the perforated pan 12 and the reflecting pan 14. Sound entering a cell through the perforations is effectively isolated since it cannot escape to the other cells through the walls of the honeycomb nor through the imperforate wall 49, nor can any appreciable amount of sound pass from the cell through the perforations. The isolated sound is effectively attenuated by the deadening material 54 within each and every cell.

What I claim as my invention is:

1. An acoustical panel, comprising a substantially flat perforated pan adapted to be exposed to sound which it is desired to deaden and having opposed sides inclined at an angle of less than ninety degrees to the inner surface of said pan to facilitate the removal of said panel from an installation thereof, and sound deadening means attached to and behind said pan with respect to the sound which it is desired to deaden.

2. An acoustical panel, comprising a substantially fiat perforated pan adapted to be exposed to sound which it is desired to deaden and having sides inclined at an angle of less than ninety degrees to the inner surface of said perforated pan to facilitate the removal of said panel from an installation thereof, a substantially flat sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back toward said perforated pan, said reflecting pan having sides forming an angle of substantially ninety degrees with the inner surface thereof, said sides contacting the inner surface of said perforated pan around substantially the entire periphery of said panel to prevent the escape of sound from the edges of said panel, and a light weight semi-rigid core between said perforated pan and reflecting pan and secured to both said pans for deadening said sound and adding strength and rigidity to said panel.

3. An acoustical panel, comprising a substantially fiat perforated pan adapted to be exposed to sound which it is desired to deaden and having sides inclined at an angle of less than ninety degrees to the inner surface of said perforated pan to facilitate the removal of said panel from an installation thereof, a substantially flat metal sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back toward said perforated pan, said reflecting pan having sides forming an angle of substantially ninety degrees with the inner surface thereof, said sides contacting the inner surface of said perforated pan around substantially the entire periphery of said panel to prevent the escape of sound from the edges of said panel, and a light weight semi-rigid core of honeycomb structure with sound deadening material within the individual cells thereof positioned between said perforated pan and reflecting pan and secured to both said pans for deadening said sound and adding strength and rigidity to said panel.

4. An acoustical panel, comprising a substantially flat perforated member adapted to be exposed to sound which it is desired to deaden, a sound reflecting member positioned behind said perforated member with respect to said sound to reflect sound passing through said perforated member and striking said reflecting member back toward said perforated member, and a light weight semirigid core of honeycomb structure with sound deadening material within the individual cells thereof positioned between said perforated member and reflecting member for deadening said sound and adding strength and rigidity to said panel, a partition abutting said panel, said honeycomb structure having individual cells of a dimension transverse the abutting partition less than the width of the abutting partition whereby the walls of the individual cells prevent sound from passing directly through said acoustical panel from one side of a partition to the other side thereof without contacting said honeycomb structure.

5. An acoustical panel, comprising a substantially flat perforated pan adapted to be exposed to sound which it is desired to deaden and having opposed sides inclined at an angle of less than ninety degrees to the inner surface of said perforated pan to facilitate tne removal of said panel from an installation thereof, a substantially fiat metal sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back toward said perforated pan, and a light weight semi-rigid core of honeycomb structure positioned between said perforated pan and reflecting pan and secured to both said pans for adding strength and rigidity to said panel.

6. An acoustical panel, comprising a substantially flat perforated pan adapted to be exposed to sound which it is desired to deaden and having sides inclined at an angle of less than ninety degrees to the inner surface of said perforated pan to facilitate the removal of said panel from an installation thereof, a substantially flat sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back toward said perforated pan, said reflecting pan having sides forming an angle of substantially ninety degrees with the inner surface thereof, said sides contacting the inner surface of said perforated pan around substantially the entire periphery of said panel to prevent the escape of sound from the edges of said panel, and a light weight semi-rigid core of honeycomb structure between said perforated pan and reflecting pan and secured to both said pans for deadening said sound and adding strength and rigidity to said panel.

7. An acoustical panel, comprising a substantially flat perforated pan adapted to be exposed to sound which it is desired to deaden and having sides inclined at an angle of less than ninety degrees to the inner surface of said perforated pan to facilitate the removal of said panel from an installation thereof, a substantially flat sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back toward said perforated pan, said reflecting pan having sides forming an angle of substantially ninety degrees with the inner surface thereof, said sides contacting the inner surface of said perforated pan around substantially the entire periphery of said panel to prevent the escape of sound from the edges of said panel, and a light weight semi-rigid core between said perforated pan and reflecting pan for deadening said sound.

8. An acoustical panel, comprising a substantially flat perforated pan adapted to be exposed to sound which it is desired to deaden and having sides inclined at an angle of less than ninety degrees to the inner surface of said perforated pan to facilitate the removal of said panel from an installation thereof, a substantially flat metal sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back toward said perforated pan, said reflecting pan having sides forming an angle of substantially ninety degrees with the inner surface thereof, said sides contacting the inner surface of said perforated pan around substantially the entire periphery of said panel to prevent the escape of sound from the edges of said panel, and a light weight semi-rigid core of honeycomb structure with sound deadening materal within the individual cells thereof positioned between said perforated pan and reflecting pan for deadening said sound.

9. An acoustical panel, comprising a substantially flat perforated pan adapted to be exposed to sound which it is desired to deaden, a substantially flat sound reflecting pan positioned behind said perforated pan with respect to said sound to reflect sound passing through said perforated pan and striking said reflecting pan back towards said perforated pan, said reflecting pan having sides extending toward said perforated pan, said perforated pan having inclined sides extending toward said reflecting pan at an angle less than ninety degrees to the inner surface of said perforated pan and laterally outwardly of certain of the sides of said reflecting pan with the free marginal edges of said inclined sides contacting outer surfaces of the latter sides of said reflecting pan, a light weight semi-rigid honeycomb core between said perforated pan and reflecting pan and secured to both said pans for adding strength and rigidity to the panel, and sound-deadening material within the individual cells of the honeycomb core.

10. The acoustical panel defined in claim 9 wherein the free marginal edges of the inclined sides of said perforated pan terminate short of the plane of the substantially fiat reflecting pan.

11. The acoustical panel defined in claim 9 wherein the free edges of the sides of said reflecting pan are in substantially continuous uninterrupted contact with the inner surface of said perforated pan around the entire periphery of the panel.

12. The structure defined in claim 4 wherein said partition abuts said panel in surface-to-surface engagement with said perforated member.

13. An acoustical panel comprising a substantially fiat perforated metal pan adapted to be exposed to sound, a substantially flat metal sound reflecting pan positioned behind said perforated pan with respect to the sound to which said perforated pan is exposed, said reflecting pan being adapted to reflect sound passing through said perforated pan back toward said perforated pan, the sides of said sound reflecting pan being turned toward said perforated pan, the peripheral edges of said sides of said reflecting pan constituting substantially a continuous margin contacting the inner surface of said perforated pan around substantially the entire periphery of the panel to prevent the escape of sound, the sides of said perforated pan overlapping and contacting the sides of said reflecting pan around substantially the entire periphery of said panel to further prevent the escape of sound, a light weight core of honeycomb structure positioned between said pans and having individual cells, said cells forming sound isolation compartments in conjunction with the opposed surfaces of the pans so that sound entering an isolation compartment through the perforations in the perforated pan is effectively isolated and entrapped so that it cannot escape the panel and cannot pass to another compartment, and sound deadening material filling the compartments, the isolated sound being effectively attenuated by the sound deadening material in each and every cell, said core being semi-rigid and secured in surface-t0- surface relation to both pans to add strength and rigidity to the panel.

References Cited in the file of this patent UNITED STATES PATENTS 1,992,509 Slidell Feb. 26, 1935 2,180,945 Morey Nov. 21, 1939 2,334,484 Dunbar Nov. 16, 1943 2,449,292 Gillett et a1 Sept. 14, 1948 2,477,852 Bacon Aug. 2, 1949 2,744,042 Pace May 1, 1956 FOREIGN PATENTS 663,897 Great Britain Dec. 27, 1951 723,621 Great Britain Feb. 9, 1955 64,827 France July 6, 1955 206,535 Australia Apr. 18, 1956 

1. AN ACOUSTICAL PANEL, COMPRISING A SUBSTANTIALLY FLATPERFORATED PAN ADAPTED TO BE EXPOSED TO SOUND WHICH 